Engine: 2.8 F/Inj B28E: - changing valves

stinky · Oct 15th, 2007, 22:18

I'm thinking about changing the valves on a B28 V6.
I've got to put a new timing chain on as the previous one snapped on one side.
As far as I can tell (it's hard to tell either way) the valves look OK, but I'm rarely that lucky. I've ordered a full gasket set in order to get the gaskets that I need, so seeing as the chain is off already and I have a head gasket is there too much risk if I take the head off and the valves out to check on the valves, maybe replace if any are bent?

I've never done this before either, so any advice is truly welcome.

Rich 264 · Oct 16th, 2007, 03:23

I have never done this; but! I have read that you have to be very careful removing the head on these as engines because of the wet liners. It is easy to disturb these liners and thus upset the seal at the liner base with unpleasant and expensive consequences! I think this is one of the reasons these engines are unpopular with garages and workshops. It is also normal practice to fit liner clamps when the heads are of for the same reason. Do lots of research before you jump in, and get a good manual if you don't already have one, theres quite a bit of info on these engines using the delorean clubs and specialists on the web. Could save you a lot of heart ache!

stinky · Oct 16th, 2007, 09:45

Cheers Rich,
I'll look into it further. I'll probably put it all together and try it before deciding whether or not the valves need changing. If it was a straight forward job I might have taken the head off but if there is risk of damaging liner seals, it could be too risky for me.

Clifford Pope · Oct 16th, 2007, 13:29

I don't know this engine, but surely you can test the valves without taking the head off?
Compression test, with and without thick oil injected into the cylinder.
"Rope trick" to hold the valve while you release the spring, then lower a fraction and check the stem for side-play and straightness.

Mister T · Oct 16th, 2007, 14:13

Stinky,
Instal the chains first and then before installing the front cover do a compression test on the left bank , do you have the instructions for the chain installation ?.
Mister T.

stinky · Oct 16th, 2007, 22:39

I have a haynes manual which is good but not perfectly clear.

davebslater(uk) · Oct 16th, 2007, 23:11

http://www.ultrapartsltd.co.uk/Appguide/Web_Index.htm

might find what you want in there

stinky · Oct 17th, 2007, 11:45

Thanks Dave,
it's been difficult finding parts for this engine; I've been buying most of the stuff from the Delorean guys. Ultra Parts seems to have all the necessary bits which is nice. Cheers.

Oct 15th, 2007, 22:18	#1
stinky Member Last Online: Sep 18th, 2011 00:59 Join Date: Dec 2006 Location: Havercroft, Wakefield	changing valves I'm thinking about changing the valves on a B28 V6. I've got to put a new timing chain on as the previous one snapped on one side. As far as I can tell (it's hard to tell either way) the valves look OK, but I'm rarely that lucky. I've ordered a full gasket set in order to get the gaskets that I need, so seeing as the chain is off already and I have a head gasket is there too much risk if I take the head off and the valves out to check on the valves, maybe replace if any are bent? I've never done this before either, so any advice is truly welcome.

Oct 16th, 2007, 14:13	#5
Mister T Senior Member Last Online: Sep 12th, 2019 23:23 Join Date: Sep 2007 Location: San Diego	Mister T Stinky, Instal the chains first and then before installing the front cover do a compression test on the left bank , do you have the instructions for the chain installation ?. Mister T.

Oct 16th, 2007, 23:11	#7
davebslater(uk) redbollock guru Last Online: Jun 30th, 2016 23:54 Join Date: Jan 1970 Location: lincoln	http://www.ultrapartsltd.co.uk/Appguide/Web_Index.htm might find what you want in there __________________ www.dbsmotorsport.co.uk

Oct 16th, 2007, 03:23	#2
Rich 264 Pinball Wizard Last Online: Feb 6th, 2013 00:53 Join Date: Dec 2002 Location: cheshire	I have never done this; but! I have read that you have to be very careful removing the head on these as engines because of the wet liners. It is easy to disturb these liners and thus upset the seal at the liner base with unpleasant and expensive consequences! I think this is one of the reasons these engines are unpopular with garages and workshops. It is also normal practice to fit liner clamps when the heads are of for the same reason. Do lots of research before you jump in, and get a good manual if you don't already have one, theres quite a bit of info on these engines using the delorean clubs and specialists on the web. Could save you a lot of heart ache!

Oct 16th, 2007, 09:45	#3
stinky Member Last Online: Sep 18th, 2011 00:59 Join Date: Dec 2006 Location: Havercroft, Wakefield	Cheers Rich, I'll look into it further. I'll probably put it all together and try it before deciding whether or not the valves need changing. If it was a straight forward job I might have taken the head off but if there is risk of damaging liner seals, it could be too risky for me.

Oct 16th, 2007, 13:29	#4
Clifford Pope Not an expert but ... Last Online: Yesterday 08:48 Join Date: Dec 2001 Location: Boncath	I don't know this engine, but surely you can test the valves without taking the head off? Compression test, with and without thick oil injected into the cylinder. "Rope trick" to hold the valve while you release the spring, then lower a fraction and check the stem for side-play and straightness.

Oct 16th, 2007, 22:39	#6
stinky Member Last Online: Sep 18th, 2011 00:59 Join Date: Dec 2006 Location: Havercroft, Wakefield	I have a haynes manual which is good but not perfectly clear.

Oct 17th, 2007, 11:45	#8
stinky Member Last Online: Sep 18th, 2011 00:59 Join Date: Dec 2006 Location: Havercroft, Wakefield	Thanks Dave, it's been difficult finding parts for this engine; I've been buying most of the stuff from the Delorean guys. Ultra Parts seems to have all the necessary bits which is nice. Cheers.

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